Posts Tagged ‘Teaching’

Fall term is now past its midpoint. Last week I gave my first midterm exam (a second one will be administered on the last day of classes), and the class average was remarkably close to that of the midterm which I gave two years ago, when I taught the same course. Back then enrolment was 198, this time around it is over twice that.

The following scene has taken place, pretty much as described, several times over the past fourteen years — obviously the details vary from time to time, but the canvas is always the same: I am helping a freshman physics student in my office. The person came to ask for help or clarifications, typically on a homework problem.Me: OK, so, we are then left with the following ratio, where you have at the numerator g, and at the denominator the square root of g. The ensuing simplification leaves us with just the square root of g…Student: Excuse me… how did you get that ?Me: You mean, how did I arrive at that ratio ? OK, let me redo the algebra for you…Student: No, I have followed up to this point… but, how do you go from the ratio to having just the square root of g ?Me: Well… um… you have g at the numerator… its square root… at the denominator… (I can tell that the person is not following… stares at the paper as if it contained hieroglyphs)Student: I am sorry, I do not understand… how does that work ?

On September 9, 2010, I started teaching my largest physics class ever (412 enrolled). Until now, the largest I had taught was 200, and I thought that that was still “manageable”, in a way. The room was big, but there were still white boards, I could be heard without using a microphone; I graded myself midterm and final exam (problem-based), and even though it was time-consuming, it was still doable. Doubling the size, however, seems to change the ballgame, somewhat. These are my impressions thus far:

Having described in my previous post the most important deficiencies of problem-based tests (as I see them), I am now going to list what I perceive as the most important merits of Multiple Choice Tests (MCTs), and illustrate why I regard them as a better choice, especially for introductory, foundation type courses. Here too, in order to keep the discussion concrete I shall focus on physics tests.

When I started teaching, in 1996, I never imagined that I would some day make use of multiple choice tests (MCT). To me, multiple choice would be a tool to conduct surveys, possibly suitable to test one’s proficiency with road signs and traffic rules, or other subjects requiring simple memorization — surely not a person’s mastery of a subject like physics.

It was 1997, and I, like many other science postdocs, was looking for my first tenure-track position. I had been a postdoc for five years at that point, and the academic job market in physics did not look any better in those days than it does now. Contingency plans were in order for anyone in my position not living in a fantasy world. After much pondering, and lengthy discussions with my very supportive spouse, I came to the decision that that was going to be my last attempt — in case of failure, I would switch to a different career, possibly in finances, a sector which at that time seemed to absorb many wannabe physicists.

Since 1996, when I taught my first course at the college level, I have always set up a web page for the courses I taught. It has never really been an issue to me, whether I should do it or not — it seemed like a no-brainer. I mean, really, why would anyone not take advantage of a technology that allows a teacher to provide quickly and efficiently updated course information to all enrolled student ?

It’s funny how some people think that, because absence of evidence does not mean evidence of absence, it must mean evidence of presence…
(A graduate student in my department)

“The best researcher does not necessarily make the best teacher” — This is a contention that I have heard many times, made both by students and academics. It is difficult to dispute it, especially if phrased as above. We all have had bad experiences with university professors who may have been reputable scientists or scholars, but were simply not gifted classroom teachers. On the other hand, there exist individuals who do not possess or display any remarkable talent for research, but who nonetheless seem to prove able instructors, at least based on what have come to be accepted as reliable measures of teaching effectiveness. That this is true is hardly surprising — to any rule having to do with humans there are exceptions.

A recent article in The Big Money (from Slate) rehashes a prediction that many have been making over the past decade.
The growth of online universities, offering courses that can be taken where and when it is convenient, leading toward accredited degrees, at a fraction of the price for the same degree at a conventional university, will soon lead to the disappearance of the traditional college experience. Universities, with their campuses, highly paid deadwood, er, professors, dormitories, schedules, classrooms, fraternities, sororities, partying and football teams, may soon become a relic of a time past.

A problem with graduate textbooks, especially in the sciences, is their cost. It is quite common for a graduate student to shell out several hundred dollars to purchase required textbooks for graduate courses. In fact, because graduate courses are typically taken early on, when a student is fresh in graduate school and may not have yet acquired the necessary cash management skills, this expense can deal a serious blow to a student’s finances.